Glass bending apparatus



Nov. 26, 1957 Filed 001;. 5, 1952 F. J. CARSON ETAL GLASS BENDING APPARATUS 3 Sheets-Sheet -1 as 55 54 9 54 s2 l F. J. CARSON ETA]- GLASS BENDING APPARATUS Nov. 26, 1957 3 Sheets-Sheet 2 Filed 06. 3,-1952 ON Q Q Nov. 26, 1957 F. J. CARSON ETAL GLASS BENDI-NG APPARATUS s Sheets-Sheet 3.

Filed Oct. 5, 1952 GLASS BENDING APPARATUS Franh J. Carson, Toledo, and Gerald White, Rossford, Ohio, assignors to Libbey-Owens-Ford Glass Company, Toledo, Ohio, a corporation of Ohio Application October 3, 1952, Serial No. 312,922

12 Claims. (Cl. 4967) This invention relates broadly to the bending of sheets or plates of glass to a desired curvature. More particularly, it relates to an improved multi-section, hinged type bending mold.

In the bending of fiat glass sheets to rather severe U shapes, difficulties have been encountered in causing the sheets to conform under the influence of heat and gravity to the desired curvature. Therefore, it has been proposed to support the glass sheets when flat above a multisection, hinged type bending mold and to cause the severely bent portions of said sheets to be urged into proper conformity with the shaping surface of said mold by the influence of sections of the mold itself upon said ends of the sheets during the bending thereof.

To be more specific, it has been proposed to bend relatively long fiat glass sheets to severe U shapes by means of hinged type bending molds having means for initially locating the ends of said sheets above the mold when fiat and then urging the severely bent portions of said sheets into conformity with the mold during the actual bending thereof. In operation, the sections of a bending mold of this type are movable from an open, spread-apart position for receiving and locating a flat glass sheet to a closed position in which said sheet is bent into conformity with the shaping surface of said sections.

Further difliculties have been encountered when the sheet to be bent is of a pattern or outline having relatively sharp V shaped end portions, the apices of which are substantially offset from the longitudinal center line of the sheet. In such a case, the means for initially locating the ends of the sheet preparatory to bending are necessarily disposed at the apices of the very extremities of the mold in order to provide a wedging effect on the sharp V shape of the ends of the glass sheet. When so located, it will be understood that there is a decided tendency for the unbalanced flat sheet to tilt away from the side toward which said means is disposed and thus to slip from its position above the mold.

It will further be understood that the end portions of the bending glass sheet are caused to undergo a significant change with respect to the side portions. That is to say, as the end and side portions of a glass sheet, having a pattern of the type described, are lowered onto the mold, the end portions are caused to simultaneously change in angular relation with respect to said side portions. To put it another way, the end portions of the sheet are not only swung downwardly in a vertical plane but are also more or less twisted or turned in a horizontal plane. Due to this constantly changing angular relation even further difficulty has been encountered in maintaining the sheet in properly located position with respect to the mold during the actual bending thereof.

It is, therefore, an object of this invention to provide an improved hinged type bending mold by means of which a glass sheet of the pattern described may be properly balanced in operative position above said mold.

,Another object of this invention is to provide an improved hinged type bending mold which will support a flat glass sheet of the pattern described above said mold in a substantially level position.

Still another object of this invention is to provide an improved hinged type bending mold having means associated therewith for supporting the unbalanced sides of a fiat glass sheet of the pattern described in proper relation above said mold.

Still another object of this invention is to provide an improved hinged type bending mold having means associated therewith for supporting a flat glass in a level position above tne mold in the open position and movable with said mold in dropping below the shaping surface thereof in the closed position of the mold.

Still another object of this invention is to provide an improved hinged type bending mold having means at each end thereof for locating and maintaining the end edges of a glass sheet of the pattern described in proper relation to the mold during the bending thereof.

Still another object of this invention is to provide an improved means for locating and maintaining the end edges of a glass sheet in proper relation to a bending mold, which means is adapted to conform to and move with said end edges as the sheet is bent into conformity with the mold.

Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

According to this invention, arms are associated with the opposite end sections of a hinged type bending mold so as to be movable therewith during swinging of the mold from the open to the closed position. These arms are disposed at only the sides of the mold to which the unbalanced sheet will tend to slip and, in the open position of the mold, will be elevated above said mold to a point at least approximately level with the locating means by which the extreme ends of the sheet are supported. During movement of the mold, and particularly the end sections thereof, the arms will be caused to move downwardly below the shaping surface of the mold to permit said sheet to properly conform thereto.

By means of these arms then, the glass sheet being bent is prevented from tilting to one side and slipping from its properly supported position relative to the mold. As well, in being caused to move downwardly from their elevated positions, the ends of the arms will substantially lead the bending glass sheet so as to permit it to freely conform to the curvature of the mold shaping surface.

At the outer ends of the endmost sections of the mold, locating means for the api-ces of the sharply V shaped end portions of the glass sheet to be bent are mounted on said sections so as to be universally movable with respect thereto. in this manner, said means maintain their wedging effect on the end portions of the sheet as said sheet bends into conformity with the mold and said end portions constantly chan e in angular relation with respect to the side portions of the sheet.

in the drawings, wherein like numerals are employed to designate like parts throughout the same:

Fig. 1 is a plan view of a hinged type bending mold of the type described in the closed position and showing the supporting arms as Well as the locating means associated With the end sections thereof in accordance with this invention;

Fig. 2 is a longitudinal sectional view of the bending mold of Fig. 1 taken substantially along the section line 22;

Fig. 3 is a transverse sectional view of the bending mold of Fig. 1 taken substantially along the section line Fig. 4 is a transverse sectional view similar to Fig. 3

but showing the mold in the open position with a sheet of glass positioned thereover;

Fig. is a fragmentary longitudinal sectional view similar to Fig. 2 but showing the mold in the open position of Fig. 4 with a sheet of glass positioned thereover;

Fig. 6 is a fragmentary plan view of a hinged type bending mold similar to that shown in Figs. 1 to 5 but having the supporting arms associated with the end sections thereof in a modified manner;

Fig. 7 is a longitudinal sectional view of the bending mold of Fig. 6 taken substantially along section line 77 and showing in phantom lines the mold in the open posi' tion with a sheet of glass positioned thereover; and

Fig. 8 is a detail view of the locating means shown in the above figures.

Referring in particular to the drawings, there is shown in Figs. 1 and 2, an improved apparatus for bending glass sheets having patterns of the type described and designated in its entirety by the numeral 10. This apparatus includes a multi-section hinged type mold 11 swingably carried on a rack 12 by means of freely-swinging links 13.

The rack 12 is made up of a pair of end frames 14 and a pair of side frames 15 extending longitudinally between and supported from said end frames. In plan (Fig. 1) the end and side frames form the rectangular outline of the rack within and from the corners of which mold 11 is carried by the links 13.

Upstanding leg portions 16 at each end of the end frames 14 include a plurality of slotted openings 17 (Figs. 3 and 4) through which the ends of side frames 15 are adapted to extend. By means of these slots, the effective width of the rack may be varied to accommodate molds of different widths. That is, the ends of the side frames 15 are made readily removable from and interchangeable with different slots by means of wedge-shaped openings 18 in said ends through which wedges 19 may be inserted to abut against the outer sides of end frames 14. Shoulders 20 on the side frames are adapted to abut against the opposite side of the end frames to provide the entire rack with the necessary rigidity.

Projecting inwardly from ear portions 21 on the side frames 15 toward each end thereof are rods 22. The upper ends of the links 13 are pivotally carried on the free ends of said rods and the lower ends thereof pivotally carry rods 23 extending outwardly from the end portions of the mold 111. Struts 24 may be provided between said rods and other portions of the mold to reinforce the connection therebetween.

The mold 11 is of a ring or outline shape having an upper surface upon which a glass sheet G (Figs. 4 and 5) is adapted to rest when bent. This surface conforms to the marginal portions of the bent sheet and is the only portion of the mold itself with which the sheet is adapted to register during the bending operation. As well, the mold 11 may be further described as comprising a plurality of sections which are connected by hinges to permit swinging of the mold by means of the links 13 from an open position for receiving and supporting the fiat glass sheet G (Fig. 5) to a closed position (Figs. 1 and 2) into conformity with which said sheet is adapted to be bent.

In particular, the mold 11 comprises V-shaped end sections 25, to which the rods 23 and struts 24 are secured, and center section 26 composed of spaced parallel members extending between said end sections. The outer and inner peripheries of the mold sections are formed, respectively, by outer rail 27 and inner rail 28 on each of said sections. These rails are rigidly held in spaced relation by a plurality of cross members 29 extending therebetween. As well, the inner rail has a portion extending upwardly therefrom to form a shaping surface 30 on the upper edge thereof on which the marginal portions of glass sheet G are adapted to rest when bent.

The end faces of each of the outer rails 27 of the end sections and center section 26 have interfitting F-shaped members 31 formed thereon, which members are hingedly connected by pins 32. The end faces of each of the inner rails 28 of said sections are finished in such a manner as to be in abutting relation (Fig. 2) when the mold is closed. Thus, it can be seen that the mold 11 may be swung on links 13 to its open position for locating and supporting a flat glass sheet and will be maintained in that spread-apart position by the strut-like nature of said flat sheet (Fig. 5). However, as the sheet is softened by heating, it will gradually lose its strut-like character and bend into conformity with the shaping surface 30 of the mold which, in the closed position, forms a continuous ring or outline upon which the marginal portions of said bent sheet are adapted to rest.

Of course, due to the pattern or outline of the glass sheet G, the V forming the extreme outer end of each of the end sections 25 of the mold is located more nearly adjacent one side thereof than the other such that a line between said extreme outer ends would be substantially offset from the longitudinal center line of the mold. To put it another way, under ordinary circumstances, the position of the extreme outer ends of the mold relative to the longitudinal center line thereof will at least approximately correspond to the position of the extreme outer ends of the glass sheet being bent on said mold relative to the longitudinal center line of said sheet.

At the V of each of said end sections 25 are located novel, universally movable stops 33 of this invention for properly locating the glass sheet G above the mold 11 when fiat and for additionally exerting pressure on the ends of said sheet while maintaining the same in proper relation to said mold during the bending thereof. These stops 33 act as wedges in maintaining the V-shaped ends of the sheet in longitudinal position above the mold and are mounted on said end sections by means of plates 34 secured to the underside of inner and outer rails 28 and 27 and having ears 35 struck up from the ends thereof for receiving a pivot pin 36. Journaled on said pin are the legs of a U-shaped bracket 37 having a recess at its inwardly disposed end which receives a bar 38 of Marinite or other suitable material which will not fuse with glass at the bending temperatures thereof. The bar 38 is partially encased in a metal bracket and is pivotally carried by the bracket 37 in spaced relation to the inwardly disposed end thereof by a vertically extending pin 38'. As well, the face of the bar is notched at 39 to receive a similarly V-shaped portion at the extreme outer end of glass sheet G. Positive stops for upwardly and downwardly movement of bar 38 are provided at 40 and 41. The inwardly disposed, recessed portion of bracket 37 serves as a stop for the lateral swinging motion of said bar.

Alternatively, the locator bars 38 may be mounted from supports on the end sections of the mold so as to be universally movable with respect thereto, similarly to stop 33, by means of a ball-and -socket joint (not shown). For example, the locator bars and supports could be provided with interfitting ball-and-socket members, permitting said bars to be moved universally with respect to said supports and the end sections of the mold.

Thus, by this arrangement, the mold 11 may be moved to the open position and the flat glass sheet G positioned between the notches 39 of stops 33 at each end section 25. During bending of the sheet, the stops 33 are maintained in contacting and pressure-exerting relation with respect to the extreme outer ends of the sheet by the downward movement of the end sections of the mold to which said stops are secured. As well, it will be appreciated that the universal movement afforded said stops by the connections above described will permit said stops to move in conformity with said ends of the sheet to continually maintain them in the aforementioned contacting and pressure-exerting position.

It will further be appreciated that although the novel sheet edge locating means of this invention is shown in connection with a hinged type bending mold of the type disclosed, its use is not necessarily restricted thereto. That is, while said locating means has been found especially well adapted for locating the end edges of glass sheets of the particular pattern described, it also finds great utility in connection with bending molds upon which a glass sheet may be bent to other irregular shapes during which the end portions of the sheet are caused to be twisted or turned with respect to the side portions thereof.

As previously mentioned, however, when the pattern of the glass sheet being bent is such that stops 33 must necessarily be located at points along the ends of the sheet substantially offset from the longitudinal center line thereof, there is a decided tendency for the sheet to tilt and slip away from the side of the mold toward which said stops are located. According to this invention then, means are provided for maintaining the unbalanced or heavy side of the sheet on a plane at least substantially level with that of the balanced side. In other words, means are provided for both supporting said unbalanced side when fiat at approximately the same level of the stops 33 and also for leading the glass sheet during the bending thereof until the mold sections approach the closed position at which time said means will drop below the shaping surface 30.

Specifically, in the embodiment of the bending apparatus of Figs. 1 to 5, arms 42 are secured to the outer rail 27 at the unbalanced side of each of the end sections 25. Fingers 43 of Marinite or other suitable material which will not fuse with the glass at the bending temperatures thereof are disposed at the free inner ends of said arms for contacting the underside of the flat sheet to be bent.

It will be understood that upon swinging of the mold 11 to the open position, arms 42 will move with end sections 25 of said mold from the lowered position of Figs. 1 to 3 to the elevated position of Figs. 4 and 5. Thus, in order that the fingers 43 of the arms 42 be disposed in proper position to support the glass sheet when fiat at a level with stops 33 and to drop below the shaping surface 30 at a predetermined point in the bending cycle, said arms are secured to outer rail 27 at a predetermined point and at a predetermined angular disposition thereto.

It has been found that the fingers 43 will be caused to properly lead the bending sheet if the arms 42 are secured to rail 27 in such a manner that said fingers will drop below the shaping surface 30 at substantially the same time that the center of the sheet contacts said shaping surface. At this point of the bending cycle, the sheet has bent to a broad V shape preparatory to the action of stops 33 in exerting pressure on the ends of the sheet to aid in causing the severely bent portions of the sheet to conform to the shaping surface. Thus, by properly leading the sheet during the bending thereof, fingers 43 are prevented from marring or kinking the soft glass and, at the same time, serve to support the sheet when flat.

Further, arms 42 are disposed in such a manner as to support only the marginal portions of the glass sheet in order that any marks on the sheet from fingers 43 will be present only along a narrow strip of said marginal portion. For this purpose, notches 44 may be provided where needed in cross members 29 to permit arms 42 to drop into their lowered position, as best shown in Fig. 2.

When the fiat sheet G, supported in the manner described and as illustrated in Fig. 5, is heated to its bending temperature, the central portions of the balanced side thereof toward which stops 33 are disposed will first begin to bend. In this manner, the sheet will be caused to gradually lose its strut-like character and the stops will swing downwardly and twist upon their universal mounting in positively urging the sheet into conformity with the mold shaping surface. As a practical matter then,

it will be seen that as the sheet begins to bend, the tendency for it to tilt towards its unbalanced side will be overcome due to the initial bending of the balanced side as well asthe concentrated pressure exerted on said side by the stops 33, and fingers 43 on the supporting arms 4-2 may be permitted to lead said unbalanced side during the actual bending operation.

A modification of the improved bending apparatus constructed in accordance with this invention is shown in Figs. 6 and 7 and is designated in its entirety by the numeral 45. With the exception of the arrangement and construction of the supporting apparatus for the unbalanced side of the flat glass sheet G, all parts of this modified bending apparatus may be similar to the bending apparatus 11 previously described. Thus, in the interests of clarity, said parts have been assigned the reference numerals of corresponding parts of Figs. 1 to 5.

With reference, however, to the novel supporting apparatus of the modified form of Figs. 6 and 7, bent arms 46 are pivotally carried at their outer ends on stub shafts 47 projecting from the inner face of side frames 15 adjacent the unbalanced side of mold 11. An intermediate portion of each of said arms rests in a groove 48 at the outer end of a support 49 secured to and extending outwardly from the inner and outer rails of end section 25.

The neck 50 of a forked member 51 is journaled in the inner free end of each of the bent arms 46. The widely spaced prongs 52 of the fork carry fingers 53, each having a ledge 54 of Marinite or other suitable material, similarly to fingers 43. In this modified form of supporting apparatus, the side edge of the glass sheet abuts against fingers 53, while resting along its marginal portions on ledges 54, such that said fingers also serve as lateral stops in locating the flat sheet G above the mold.

The arrangement of the arms 46 and fingers 53 are such that the function thereof is similar to that of arms 42 and fingers 43 of the form of bending apparatus 10 of Figs. 1 to 5. That is, in the open position of the mold, the arms 46 are adapted to be raised to the position shown by the phantom lines of Fig. 7, in which the neck 50 of each of the forks 51 is substantially level with stops 33. In this position, the pivotally carried forks will permit fingers 53 to adapt themselves to the underside of the fiat sheet at the marginal portions thereof. As well, of course, movement of the end sections of the mold to the closed position will permit arms 46 to drop below the shaping surface 30 at the predetermined time of the bending cycle aforementioned.

It is to be understood that the forms of the invention disclosed herein are to be taken as the preferred embodiments thereof, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the following claims.

We claim:

1. In apparatus for bending glass sheets of a pattern having extreme end portions substantially offset from the longitudinal center line and toward one side thereof, a frame, a mold supported by said frame and comprising a plurality of movably mounted sections movable into an open position and a closed position, means toward one side of said mold for locating said extreme end portions of a sheet when flat, and sheet support means operably connected to a movably mounted mold section and movable with said mold section from a lowered position in the closed position of the mold to an elevated position to support the glass sheet in the open position of the mold.

2. In apparatus for bending glass sheets, a frame, a mold supported by said frame and comprising a plurality of movably mounted sections movable into an open position and a closed position which defines the curvature to which a glass sheet is to be bent, and sheet engaging arms operably connected to the endmost sections of said mold and movable therewith from a lowered position in porting position in the open position thereof.

3. In apparatus for bending glass sheets as in claim 2, including means for locating the end edges of a flat glass sheet above the mold in the open position, and supporting fingers on said arm adapted to be elevated to a position substantially level with said locating means in said open position of the mold.

4. In apparatus for bending glass sheets, a frame, a mold comprising a plurality of hingedly connected sections swingably supported from said frame and movable into an open position and a closed position, means toward one side of said mold for locating the end portions of a fiat sheet above the mold when in its open position, and sheet support means offset from alignment with said locating means toward an opposite side of said mold and operably connected thereto for supporting said fiat sheet between the end portions thereof, said sheet support means comprising arms associated with the endmost sections of said mold and movable therewith from a sheet supporting position in the open position of the mold to a position below said sections of the mold when in its closed position.

5. Apparatus for bending glass sheets as defined in claim 4, in which sheet supporting fingers are disposed on said arms so as to be substantially level with said locating means in the open position of the mold.

6. In apparatus for bending glass sheets, a frame, a mold comprising a plurality of hingedly connected sections swingably supported from said frame and movable into an open and a closed position, a shaping surface on said mold sections, stops mounted on the endmost sections toward one side thereof for locating said sheet when flat above the open mold, an arm associated with the opposite side of an endmost section and having a sheet supporting finger at a free end thereof, said arm being movable with said endmost section for raising said finger above the mold when open to substantially the level of said stops and for lowering said finger below the shaping surface of the mold when closed.

7. In apparatus for bending glass sheets, a mold support frame, a mold carried by said frame, said mold comprising a plurality of movably mounted mold sections each having a shaping surface thereon for imparting a curvature to a glass sheet, and means operablyconnected to a movable mold section for supporting a glass sheet intermediate its length, said intermediate supporting means being movable from a first position above the mold shaping surface in which it supports the glass sheet when in a fiat condition to a second position below the mold shaping surface as a bend is imparted to said sheet.

8. In a bending mold for bending pattern cut glass sheets, a plurality of mold sections having shaping surfaces formed thereon including a center section and movably mounted substantially V-shaped end sections forming continuations of said center section, said end sections being movable from an open spread apart position for receiving a glass sheet to be bent to a closed position in which the mold sections define a predetermined curvature to which the glass sheet is to be bent, and sheet supporting means secured to a mold end section and extending inwardly and upwardly therefrom, said support means being movable with the mold end section from an elevated position to support the sheet when flat to a lowered position during bending of the sheet.

9. In apparatus for bending glass sheets, a plurality of mold sections having shaping surfaces formed thereon and including a center section and end sections, said end sections being mounted for movement from an open spread apart position to a closed position in which the shaping surfaces of the end sections together with the shaping surface of the center section define a predetermined curvature to which a glass sheet is to be bent, and sheet support arms operably connected to each of said end mold sections and extending over the mold center section, said arms being movable with the mold end sections from a first position above the shaping surface of the mold center section to support a glass sheet when fiat and when the mold end sections are in the open position to a second position below the shaping surface of the mold center section when the mold end sections are in the closed position.

10. In apparatus forv bending glass sheets as in claim 2, wherein the sheet engaging arms are pivotally mounted on the mold frame for movement in a substantially vertical plane, and an arm engaging member mounted on each of the mold end sections and engaging said arms for moving said arms to the elevated sheet supporting position and to the lowered position.

11. In apparatus for bending glass sheets as in claim 2, wherein means is carried by the sheet engaging arms for engaging the glass sheet at spaced apart points, said means comprising a bar member pivotally mounted on a sheet engaging arm for movement in a vertical plane, and sheet engaging fingers mounted on said bar member and spaced from one another.

12. In apparatus for bending glass sheets as in claim 2, wherein a sheet engaging finger is movably mounted on a sheet engaging arm, said finger comprising an upwardly directed portion for limiting lateral movement of the glass sheet, and an inwardly directed portion for engaging the under surface of the glass sheet to support said sheet.

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